The nematode Caenorhabditis elegans has become an important experimental system used to study a wide variety of biological problems germane to eucaryotes. The size, limited cell number and approachable genetics has made C. elegans a highly useful organism. This proposal is to purchase a Union Biometrica Biosort 2. This instrument will both analyze and sort C. elegans on the basis of size and fluorescence; it is a "cell sorter for worms". The high capacity of the instrument in combination with its ability to discriminate worms of different sizes or expressing different fluorescent proteins permits genetic screens on a scale that was previously unknown. The capacity of the instrument to sort living worms (50,000 worms/hour) will provide enough transgenic or mutant animals to permit biochemical studies. The instrument will be used by seven different principal investigators, who belong to five different departments housed in three different colleges (College of Arts and Sciences, College of Pharmacy, School of Medicine). The instrument will be housed in our existing Fluorescence Activated Cell Sorter Facility. This core facility is centrally located on the University of Utah campus and is proximal to all of the investigators. This facility has been in operation for over ten years and is overseen by a full-time Ph.D. director and a skilled technician. The director provides training and support to users using the current Fluorescence activated cell sorters and scanners and will do so for the union Biometrica Biosort 2. There is strong institutional support for this instrument. The institution will provide the salary of the Director and the technician. In addition to space in the core facility the institution will guarantee the maintenance of the instrument. This institutional commitment will ensure that the instrument can be used by investigators without having to charge prohibitive hourly rates. The instrument's use would be monitored by an oversight committee that would manage issues dealing with priorities and publicity. The head of this committee will be a member of the Core Facilities Oversight Board. This administrative structure will provide a seamless management of the "worm sorter" within the framework of institutional Core Facilities. In summary, a fluorescent activated cell sorter for C. elegans would provide new capabilities that would greatly benefit the strong group of C. elegans researchers at the University of Utah. It would both facilitate existing research projects and permit the development of new projects that could not function without this novel instrument.